DEVELOPMENT AND EVALUATION OF A CONTINUUM NECK MUSCLE MODEL

The Finite Element method is a powerful tool for analyzing the biomechanics of the human body. One area that has attracted increasing attention is the cervical musculature and its influence in neck injury mechanisms. Most cervical FE models of today use spring-elements as muscles and are limited to discrete geometries and nodal output results. A solid-element muscle model however, will improve the geometry and add properties such as tissue inertia and compressive stiffness. It also enables analysis of element stresses and strains within the muscular tissue. The aim of this study was to determine how a continuum muscle model influences the impact behavior of a human neck FE model compared to a discrete muscle model. The 3D geometries of the neck muscles were digitized from MR images of 50th percentile males and positioned relative to the KTH FE neck model in line with anatomical data from the literature. The muscles were modeled using solid finite elements and a non-linear, viscoelastic continuum material model. The behavior of the new muscle model during impact was compared to an existing discrete muscle model for frontal, rear-end, lateral and oblique impacts. The continuum muscle model stiffened the response of the KTH neck model and improved the boundary conditions for the vertebral column compared to a discrete model.